Highs today reached 88-95. I forecasted 91-97 due to less in the way of sun & more storms. It appears that more mixing of the air (south-southwest 10-20 mph) may have cut numbers 2-3 degrees despite a lack of rain & more sunshine today.
I had a high of 93 with peak heat index of 102. Officially, at the Purdue Airport, high was 93 with a peak heat index of 100.
Heat indices ran 93-107. A bit puzzled on the Crawfordsville Airport max dew point being so low after so much rainfall in that area & nearby yesterday. Other weather stations nearby had dew points pushing 80 over the wetter soils from heavy storms with heat indices in the lower 100s. Also, wind was from south-southwest over the wetter soils, blowing toward & over the airport.
Line of storms with torrential rainfall & scattered severe gusts is moving eastward through central & northeastern Illinois.
Line show some weakening as it moves into our area, but may still be intense enough for a few isolated severe gusts as it passes after midnight to early Friday morning.
Most of Friday is dry & partly cloudy with northwest wind 15-25 mph with highs 84-90 & heat indices 87-95.
A few isolated showers & storms (25%) are possible in the afternoon to evening.
Saturday & Sunday, models are back to struggling with timing of storms after good solidarity of keeping them on Sunday, not Saturday.
I am going with Sunday with scattered storms (multi-cells & multi-cell clusters). A bit better flow aloft & shear means SLIGHT RISK parameters for wind & hail.
Highs of 86-90 are likely with heat indices 90-96 after 86-91 with 90-96 heat indices Saturday (with skies become partly cloudy).
I will pin down some actual solid time frames for storms over the weekend within the next day.
Heat wave builds in next week with widespread 90s. By Friday &/or Saturday, thinking several locations will reach or exceed 100 for actual air temperature.
On the periphery of this intense heat, multiple MCSs & perhaps a serial derecho or two are likely from the Dakota & Nebraska to Iowa, Wisconsin, northern Illinois, Michigan to northern Indiana, Ohio & then the Northeast U.S.
We need to watch the Wednesday-Thursday periods at this time.
It appears that the first MCS/derecho will stay north of our area (at least right now) Tuesday period.
However, second one may affect the viewing area, mostly likely Wednesday night to early Thursday. Main area of concern is along & north of US 24 for damaging winds.
Canadian model shows this pattern well with the brightly-colored cold cloud tops of these complexes of storms.
It is a good pattern for a couple serial derechos like in the heat waves of 2012 & 1995.
Friday afternoon projected actual air temperatures:
Saturday afternoon projected actual air temperatures:
Brief relief is possible after July 24 following storms.
However, there are signs of sudden re-strengthening of hot upper ridge & another round of intense heat.
The intense upper ridge returns for the last several days of July.
Note how the hot ridge flattens & a bit of trough swings by for those storms & some heat relief (green is the upper jet, not rainfall):
Then watch the intense ridge bulge back up with the heat wave:
A punch of better, bit longer relief should occur in the first several days of August.